Transient

D.

In And Out Of Existence

A.&C.The Word Is Transient (tran·sient) (adj) 1 a: passing especially quickly into and out of existence : From Marriam Webster Dictionary.

B.The Viking ship had such speed that to the people at land or at see it seemed as if the ship was transient and seen every once and a while.

E. Syn-fugitive, fleeting, evanescent Ant-